Home | History | Annotate | Download | only in stm32 
      1 /*
      2  * Copyright (C) 2016 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include <stdbool.h>
     18 #include <stdint.h>
     19 #include <string.h>
     20 
     21 #include <bl.h>
     22 #include <eeData.h>
     23 
     24 extern uint32_t __eedata_start[], __eedata_end[];
     25 
     26 //STM32F4xx eedata stores data in 4-byte aligned chunks
     27 
     28 static void* eeFind(uint32_t nameToFind, uint32_t *offset, bool findFirst, uint32_t *szP)
     29 {
     30     uint32_t *p = __eedata_start + (offset ? *offset : 0);
     31     void *foundData = NULL;
     32 
     33     //find the last incarnation of "name" in flash area
     34     while (p < __eedata_end) {
     35         uint32_t info = *p++;
     36         uint32_t name = info & EE_DATA_NAME_MAX;
     37         uint32_t sz = info / (EE_DATA_NAME_MAX + 1);
     38         void *data = p;
     39 
     40         //skip over to next data chunk header
     41         p += (sz + 3) / 4;
     42 
     43         //check for a match
     44         if (nameToFind == name) {
     45             *szP = sz;
     46             foundData = data;
     47 
     48             if (findFirst)
     49                 break;
     50         }
     51 
     52         //check for ending condition (name == max)
     53         if (name == EE_DATA_NAME_MAX)
     54             break;
     55     }
     56 
     57     if (offset)
     58         *offset = p - __eedata_start;
     59 
     60     return foundData;
     61 }
     62 
     63 static bool eeIsValidName(uint32_t name)
     64 {
     65     return name && name < EE_DATA_NAME_MAX;
     66 }
     67 
     68 static void *eeDataGetEx(uint32_t name, uint32_t *offsetP, bool first, void *buf, uint32_t *szP)
     69 {
     70     uint32_t sz = 0;
     71     void *data;
     72 
     73     if (!eeIsValidName(name))
     74         return false;
     75 
     76     //find the data item
     77     data = eeFind(name, offsetP, first, &sz);
     78     if (!data)
     79         return NULL;
     80 
     81     if (buf && szP) {    //get the data
     82         if (sz > *szP)
     83             sz = *szP;
     84         *szP = sz;
     85         memcpy(buf, data, sz);
     86     }
     87     else if (szP)        //get size
     88         *szP = sz;
     89 
     90     return (uint32_t*)data - 1;
     91 }
     92 
     93 bool eeDataGet(uint32_t name, void *buf, uint32_t *szP)
     94 {
     95     uint32_t offset = 0;
     96 
     97     return eeDataGetEx(name, &offset, false, buf, szP) != NULL;
     98 }
     99 
    100 void *eeDataGetAllVersions(uint32_t name, void *buf, uint32_t *szP, void **stateP)
    101 {
    102     uint32_t offset = *(uint32_t*)stateP;
    103     void *addr = eeDataGetEx(name, &offset, true, buf, szP);
    104     *(uint32_t*)stateP = offset;
    105     return addr;
    106 }
    107 
    108 static bool eeWrite(void *dst, const void *src, uint32_t len)
    109 {
    110     return BL.blProgramEe(dst, src, len, BL_FLASH_KEY1, BL_FLASH_KEY2);
    111 }
    112 
    113 bool eeDataSet(uint32_t name, const void *buf, uint32_t len)
    114 {
    115     uint32_t sz, effectiveSz, info = name + len * (EE_DATA_NAME_MAX + 1);
    116     bool ret = true;
    117     void *space;
    118 
    119     if (!eeIsValidName(name))
    120         return false;
    121 
    122     //find the empty space at the end of everything and make sure it is really empty (size == EE_DATA_LEN_MAX)
    123     space = eeFind(EE_DATA_NAME_MAX, NULL, false, &sz);
    124     if (!space || sz != EE_DATA_LEN_MAX)
    125         return false;
    126 
    127     //calculate effective size
    128     effectiveSz = (len + 3) &~ 3;
    129 
    130     //verify we have the space
    131     if ((uint8_t*)__eedata_end - (uint8_t*)space < effectiveSz)
    132         return false;
    133 
    134     //write it in
    135     ret = eeWrite(((uint32_t*)space) - 1, &info, sizeof(info)) && ret;
    136     ret = eeWrite(space, buf, len) && ret;
    137 
    138     return ret;
    139 }
    140 
    141 bool eeDataEraseOldVersion(uint32_t name, void *vaddr)
    142 {
    143     uint32_t *addr = (uint32_t*)vaddr;
    144     uint32_t v;
    145 
    146     // sanity check
    147     if (!eeIsValidName(name) || addr < __eedata_start || addr >= (__eedata_end - 1))
    148         return false;
    149 
    150     v = *addr;
    151 
    152     //verify name
    153     if ((v & EE_DATA_NAME_MAX) != name)
    154         return false;
    155 
    156     //clear name
    157     v &=~ EE_DATA_NAME_MAX;
    158 
    159     //store result
    160     return eeWrite(addr, &v, sizeof(v));
    161 }
    162